Bifunctional 4MBA mediated recyclable SERS-based immunoassay induced by photocatalytic activity of TiO2 nanotube arrays.
Phys Chem Chem Phys
; 18(34): 23795-802, 2016 Sep 14.
Article
en En
| MEDLINE
| ID: mdl-27523026
ABSTRACT
We first report here a novel recyclable surface-enhanced Raman scattering (SERS)-based immunoassay via the photocatalytic ability of anatase titania nanotube (TiO2-NT) arrays. In this immunoassay, an immune probe was realized by immobilizing anti-CA19-9 onto Ag@SiO2@Ag three core-shell nanoparticles (TCSNPs), which showed a much higher SERS activity than bare Ag NPs with an enhancement ratio of 1.75. Then, the vertically oriented TiO2-NT immune substrate was synthesized by ultra-fast anodic oxidation of flexible titanium foils and functionalised with 4-mercaptobenzoic acid (4MBA) molecules to link them with anti-CA19-9. The immunoassay using the above immune probe and the substrate exhibited a wide linear range from 1000 to 0.5 U mL(-1) and a low detection limit of 0.5 U mL(-1) for CA19-9 due to the excellent SERS performance of Ag@SiO2@Ag TCSNPs. More importantly, the linkage between TiO2-NTs and 4MBA was destroyed by catalyzing 4MBA into 4-sulfobenzoate upon UV irradiation in O2-saturated water. The target antigen and the immune probe were simultaneously removed leading to a recyclable immunoassay and a detection limit of 5 U mL(-1) was achieved after six cycles. The simplicity and versatility of this strategy may bridge the technology gap between academia and practical detection, which makes it promising for clinical SERS-based immunoassay.
Texto completo:
1
Base de datos:
MEDLINE
Asunto principal:
Espectrometría Raman
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Compuestos de Sulfhidrilo
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Titanio
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Benzoatos
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Inmunoensayo
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Antígeno CA-19-9
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Nanotubos
Idioma:
En
Revista:
Phys Chem Chem Phys
Asunto de la revista:
BIOFISICA
/
QUIMICA
Año:
2016
Tipo del documento:
Article